Pressure equalizer for air-brake systems



July 27,1926. f 11, 16,395

' F. J. SPRAGUE' n ussm iouuxzmroa AIR am: srsrsns ou um Filed bee. 31 1914 Mam I Y RESCPWIP F/gl s A TI'ORNEYS.

iii

V on the locomotive y as the brake pipef Reissued July 27, 1926.

UNITED STATES PATENT OFF-ICE.

FRANK J. SPRAGUE, OF ,NEW YORK, N. Y.,

ASSIGNOR TO SPRAGUE SAFETY CONTROL AND SIGNAL CORPORATION, A CORPORATION .OF VIRGINIA.

PRESSURE EQUALIZER FOR AIR-BRAKE SYSTEMS.

Original application filed December 31, 1914, Serial 1925, Serial No. 34,703. Original No. 1,553,295 filed March 22, 1926. Serial No. 96,658.

This application is filed as a divisional of my prior application filed December 31, 1914, Sr. No. 879,1-39, for method of an ap paratus for controloi train movement, and thesuhject matter hereof -forms a part oi theapparatus disclosed in the aforesaid prior application, whereby under certain conditions the air pressures, as in the equalizingreservoir and brake pipe, are'equalized. Inthis application such subject mat ter is disclosed and claimed Without reference to the question of automatic train control, in that the invention embodied herein is capable of use-independently of the con- In my prior application referred to the automatic brake system upon which my invention is shown as superimposed is the ordinary form embracing what islknown as the \Vestinghouse G G engineefis valve, this valve being' chosen for, simplicity of illustration and :WitllOLll/ intended limitations. Brie-fly jstated that system comprises the followingfelements:-

One or two main reservoirs carried (Ii) A pipesysteni consisting otair pipes individual to, each and Joined cont nuousl from car to car and collectively known The engi iieersvalve, .itsiequal- 12mg piston, "equal zlng cl iambe-r and reservoir and feed valve, connected w th the main reservoir and the brake pipe, "and controlling the latter, its function depending upon the position of the handlepf'the' reservoir into the bra gineeifs valve normally has five positions.

nainely'i -running the normal position 0 the va when. the" min i running unbr'aked release, the osition of the valve for recharging the brake 'pipe and efitlctin release of the brakes; lap, in which all ports in the rotary valve are blanketed, there being no feedin of airfimmt m s Pin nd-no sc p ofair-from the-equalizing reservoir se. 1'-,v-

ice, in which air is, ,hled :trom the, brake cylinders; trol of standard equipment by automatic No. 879,939. -Divided and application filed June 3,

, dated September 8, i925. Application for reissue pipe at a low rate'toeffect service braking,

the valvel'iandle being normally moved from service position to lap position to delLlJ'lllIlfi the amount of service braking; and emergency, in which the brake pipe is freely bled to atmosphere through a large port in the engineers valve to effect emergent-y braking; i 5 '(rl) Brake cylinc ers individual to each car for directly applying the brakes through the'foundation gears-lid braking rigging; (6) Auxiliary reservoirs i'individual to each 'car fer -supplying air to the brake Triple valves individual/to eachcnr for controlling ,the' brake cylinders in response to changes in the brake pressure:

(g) A duplex'indicating air gauge for showing the air pressure in the main re sei voir and equalizing reservoir;

(h) A conduttofs valve connectedwith the brake pipe system which may beopened to atinos iihei'e, producing qi'iasi-e-mergency braking such as is producedwhen. an air hose in the brake pipe burstsor a train pulls apart. 1

The movement. of air Ii1 1 standard: bri1king equipment such as above outlined under certain Conditions may result in adi'l'tforential of pressure on the two sides of the equalizing piston of the engineers valve which is detrimental to the action of the system. It this detrimental action which it is the object of this invention to correct.

Referringto the 'ac'comp anyin'g drawings in which corresponding parts are designated bycorresponding marks of reference:

F 1 is a diagrammatic view of an-engin eers valve incorporating my "invention and showing the valve in running position, the main reservoir, equalizing reservoir, duplex nirgauge and 'lieed valve being illustrated. j' I Fig. 9 is a diagrammatic view o -fth e enginee1- s valve (and iced valve),,-in lap-position. a I? 3,4 i nd'5 lire diagrammatic views :r' to Fig. 2 showing the'enginers.

valve in release, service and emergency positions respectively.

Referring to Fig. 1, the main reservoir has a pipe connection 2 through which air delivered into it and compressed "therein by 1". automatically 'pressure-controlled pump, not shown. On the opposite side of the main reservoir is a pipe connect-ion 3 which leads from. the main rcseiwoir into pipe 1, which coi'i'ninunicates with a passageway 5 in the en ineers' brake valve "leading to chamber 6 in the top thereof.

The Cl'lfllilbl 6' is shown dia raininat'ica'lly in the whim. ol' the rotary viiae 7, and the valve seat is shown surrounding the periphery of the rotary element in place of beneath it, as in the physical embodiment of the valve, the rotary element itself being shown with radiating passages and peripheral cavities in @il-ace oi the more or less vertical cori' spon ing elements in the physical construction.

The valve body 10 of the engineers brake valve contains passageways 1'1, 12, 13 and 14, and an emergency exhaust port 15, all communicating directly with the seat for the rotary valve 7. In this seat also is chain- 'ber 16, which has no communication with the atmosphere except through the rotary valve, and a chamber 17, which isin (.0111- Inun'icatio n with't-he atmosphere through the emergency exhaust port 15. The passageways 11 and 12' lead respectively to and from a feed valve 18. In the bottom of the e'ng'ineers "valve is an equalizing piston chamber '19. Passageways 13 and 1% lead to and from this chamber respectively at the top thereof. This cha'inber also at its top is provided with a port 20, and the bounding walls of the chamber constitute a cylinder within which reci'procates an equalizing 'pist0n21. The equalizing piston carries a service exhaust valve 22 which opens and closes a service exhaust port 23 leading to atmosphere on the one side, and coinmunicati ng with a passageway 24 leading to the upper side of the equalizing piston 21 and connecting also with the passageway 12 totlte valve/and to the brake pipe.

The rotary valve 7 has three passageways 26, 27 and 28"radi'ating from chamber 6,-a'nd two cavities29aifd 30 on'its periphery. Port 21) is the port which communication is made between the'eq'lia liz'i'ng piston chamber 19 and an equalizing" reservoir by means of a r p .2-

A du- -1e'x air gauge 33. above 'referred'kto, is suits ly con nect'ed with the main reservoir through aibranch from pipe 4 and with the equalizing reservoir through a branch from'.pi'pe 32.

'Fhe rotary valve 7 is manipulated by means of a spindle (not shown) to the top of which "is attached the engineers handle (not Slldwfi).

Considering the ordinary practice and operation recited above the live positions of the (it-(5 engineers brake valve-running, lap, service. emergency and release, are indicated as tollows:

Run 11mg position.

In "Fig. 1 the rotary valve 7 is show-1r diagrammatically in running position. The passageway 26 01" the rotary elei'nent registers with the blind chan'iber 16 and is blanls etecl. The passagexwtyflii is also blanketed; but the passageway 2'? registers with the passageway 11 in the va'li' e body, and thus permits a flow of air from the main reservoir into the feed. valve 18, and thence into the brake pipe through the passageway and 24. The passageway 12 is in communi cation with the passageway 13 through the cavity 29, thus permitting air from the -feed valve to fio'w into the equalizing piston chamber 19' and thence into the equalizing reservoir: The passageway ltfl'IlCl the emerg'ency port- 15 are both blanketed. The same pressure is then maintained in the equalinin'g piston chamber and the equaliizng reservoir as in the brake pipe and beneath equalizing piston 21, and the service 'haust valve 22 is maintained in its down-- ward position, closin' the service port 23. No air escapes from the brake pipe and the brakes are free.

Lap position.

In Fig. 2 the rotary valve is shown diagrammatically in lap position. The passageway 26 registers only with the blind chainber 16 and is blanketed; the passageways 2'7 and 28 are both blanketed. The passagesays 111 13 and 14. and the emergency exhaust port 15 are also blanketed. There is, thereforano flow of air from the main T8861- voir into the brake pipe or the equalizing "piston chamber either directly or through the feed valve, and no flow of air from the equalizing piston chamber. On coming from lap to service position, the service exhaust va 've 22, on equalization of pressure due to the drop of pressure in the brake pipe, is moved downward from the position it has at "the-commencement of the lap position of the enghieers valve by its weight and a slight excess of total pressure of air above the equalizing iston, closing the service exhaust port (see ig. 2-) andafter closing, it remains closed as long as lap position is maintained; in coming to lap position from running position the service port 23 is already closed.

Service position.

Service position is indicated in Fig. 4:, which shows the rotary valve rotated fur ther counter-clockwise until the passageway 14 registers with the cavity 30. The pas- -:sageway-'26 registers withthe blind cavity ldmdisstih blanketed. Thai ge'ways 27mm} 28 blanket" 1 Blfi0n51hhQ'mflin reservoir is'thuscut o cm the feed valve; brake p'ipefequalizing piston chamber 19 equalizing reser- Thetglssageway 13 is also blanketed v: 14 d h a" K ssag'e ay t e emergencyport" ilms; squalifing chamber and the '-"-8qIlflllZi1Ig' m1'-V0il' ere opened to atmosphere. Service position is normally reached iron or through lap position, i. e., a position in .which service exhaust port 23 is closed. s -When the engineer makes a service appli- -eation, he reduces that-pressure in the us]- izingf-redervoirsnd e equalizing piston -rhamher=hy=the number-of pounds which he a I YR: -toreduce in *the brake pipe, which re- '20 of pressure will-he indicated by one of the'hands-oftheduplex air gauge 33, that handrbeinghlack in erdinary practice. As pressure is reduced in the ualizing j pistonflchamberthe air ressure in e brake pipe; the r side of the equal-' 'ston, raises it together-with the servaust-jvelve 223ml opens the service ex lilustpofltllil to' atmosphere, allowing the' *nir'to *escape-therethmugh from the brake 7bit."

infi l dea-is thus raised depends a n the yrs rty withwhieh the difierential {the ofthe pisto fand eiflthe' hottom of the equalizing piston 1: as; la eside. S0 league the equalizing reservoir 1nd the eqiializing piston chamber are open te a p ere *by-the'rotary valve-being u r insinta'inedfhi service port'28 willbeski o q provided temainmin the ualizing piston in its up *ward' "tion': en; the reduction desired in hrs a pressure has'been indicated by the ga'uge-connectedwith the equalizing pis- '-ton'-'ehambsr and the equalizing reservoir normallyinoves-his andle into position; passagway'-' 14 having been cloaedby doingso'nnd further escape 4 of sir fmm the equalizing iston chamber r "5 the equalizing vented,

" *thep oftheaiflin'the equa ingreservoir will beexerted on the top iston', amt-as m wthe -pres- I ohm pipeonthe under 1 F side of: the eqnafziughpiston is reduced *to the same pressure as at in' thefequilizing service ex-" A hsnstvalve m-will'elose-theservtce g8.=*'-'Ehereiore, the reduction of airplessfll'' 'in the mallzlhgweservflia, rinority made bypatting the rotary 'valve in tion, is a measure of the'mducsr'ibsequently follows in the brake 35 pipe. whichit will take for this lasso .Asinla clvity' 30 'registersboth with sq pi'pw lherapidity with which the 'equalizawise nintil 'tion the service" I p I .chamber-16,-'cavity 29 also registers with #40 thereis eut pressure in t e brake-piprreservoir; to a n ligible Emergency position. The emergency position of the rotary valve is illustrated in 5. a This is the extreine braking itionfof the valve, and it .is -POS8lb6 to comerto it from or throu service position by movin the r0- ta valve counterclockwise from t e latter. The leaves the ports in the rota blanketed, although in a slight y difierent position so thatthere is still no flow of prossure'iair. into the brake ipe and the main reservoir is not bled. e emer my exhan'st port 15 is connected throng the cavity 29 with the way 12 so that a free 11 from to atmosp re. exhaust rt 15 18 also connected by the chamber l'l imd the cavity 30 with the assageways- 14 and 11. This results in re 'eving thepressure on the top of the equalizin piston and revents a possible jamming oiservice e aust valve.

' Release position.

The release position of the rotary valve is illustrated in 3; After the brakes have been applied itzis only possible to come to release-position from or through running position, by moving the rotar valve clock- Eessageway 11 is lanketed and air from 1; main reservoir is prevented from flowi into the feed valve; passageway 26-.an cavity-29 both register with zeegew'ays Band-12,1114 Pa y 27 registers with passageway 14.- ir thus flows freely from the main reservoir. through passageways Hand 14 to the ualizi piston chamber 19 and thence to e equa i-zlng reservoir: and through passageways 12 and 24 into'thebrake pipe, recharging both the equalizing reservoir and the brake pipe. On going 'to release position the service exaust port 23 is normally closed by the service exhaust valve 22, as'above set forth; and it h remains closed, for anydifierential of prost e sure which may exist in that position with respect to the equalizing Eaton is in favor of-thetop of the pistom e pamageway' 28 registers with the emergency port 15', and a small amount of air from the main reservoir therethrough with a hissing noise, warning the engineer not te -overcharge the zstem. v Bywatchingthe 'black hand of the plex-air gauge the increasing pressure inthe brake pipe while retainin "the rotary 'valve in release position,-and w the desired pressure is registered return the rotary valve to running position.

the engineer can determine valve still Huf m the srvioe exhaust valve '22 to jamor stick. .'I have provided meme which take -cmof-flwse conditions when oemtain di flver- 'entiml'pressures exist on the two sidaesof the u ualizing piston tending to client this jam- 'lifim mums comprise a: relief valve-eon- 'weefled between the brakepipe system and *the equalizing piston chamber and equaliming-lrem'voor. the-who 'bodyi225 ismonneoted onthe one side'by a '19s 2% the'riser of the brake pipe, on en the other stale a pipe 227 with 'the piston elm er and reservoir. I

'fliereiiefvalve 228 has-a seat o'f-the ordinary form and opens rwway from-the equali reservoir, being normally maintained against-its mtflflfiby a helical spring 230, the tension of 'wrlia'oh ismegu lated by s'sorew cap 231 so formed as to provide a guide for the valve and a seat for the spring. This 30 sprin need" only be o'fi'sufieient strength to keep' valve closed when air preemies are eqfllon bdth' aides bhereofl; TM shim of the val vedaepends on a, iii'ifeienlmul or air pressure on the twoieides :zs-uhereuu, Since, in the runn ng 'p j the"!!! 'ne'efls v the presume in the equakizm lhunlber and reservoir is the saline :as 'n'tho remain olosai 'lurd, 'a1so,:no-flow of air will takepiaee thrmgh 'the valve so long as the Wesson on the equalizing reservoir side is dose than the pressure on the brake pipe side,

as is theoa'se 'bdth at the moment of begin- -ui Ium1al service and emergency brake icatious; not, obviously, will any flow =0! thefhraiies is being :held.

When therfn'essure on the brake pipe side 0! the 'mlief valve is =less than that of the engmoer;s-valve,.-the combination with the dqual' reservoir side, the valve opens 'lld remains until these pressures are nearly This equahwing of the pressures is parallel imirespectto the equalizing vpiston, "ind the service exhaust v-al v'e-i's ther ebgy :pre-

T551 vented -fm jmmning 'or stidkling Io-has beenmn thatthismay'occhlr in releafi posiit my #180 occur whe -hm brake rpn' is opened external to the engineers wise, ns, ffdx'etmmple, w vthe cond uetors who a opened ortlaebrakepi-pe :is

'ae abone set forth.

mi wilsl' be noticed thmtthe memes e ilhstmd asex tending upward 11d 'itejunttiou'! with the main reservoir, and that there is a pipe extension at the right As illustrated in Fig. 1-

32 leading to tlhe equalizing akae :pipe, the relief vwlve228 will- 3 air take place while] service application muses to the lowerend of pi lhese extensinus. have todo with-t e automatic control system-set forth in the aforesaid application hat I claim'as new and desire to secure by Letters Patent. is:

.11. In aiua-ir broke systemfthe combina- -tion of avmain reservoir, an equalizingres- ,ervoir, a; brake pipe, nornwlly-olosed con- :necting means between-the equalizing reservoir' and the brake pipe opened when the pressure 1 in the equalizing reservoir is in exoessof that in the brake pipe, a feed valve andnieans for changin the equalizing reservoir-and brakepipe rom the main resorvoi-r through the teed va'lyve when 'thenormolly olosed connecting means is 'olosed.

2. hem airfhrake :systengthecombination-of a main reservoir, an equalizing reservoir, a brake ipe, a normallyclosed by- ;pass between t ,r-equalliz ng reservoir and thebBakepipe -opened whenthe pressune'in itheequalming reservoir is in excess of that till the brake pipe, of feed valve audjmeens for ohargiing the equalizing reservoir and brakepipe from the main reservoir through Jthe-zfieed valve when the by-pass is closed.

3.111 on air? brakesystem', the combination ofa main reservoir, an equalizing reservoir, a brake. pipe, connecting means between theequallizing reservoir and the brake pipe biased to closed.- position'when thepmssores in the equalizing reservoir and brake .pipe :are equal andopened whemthe pressure in the equalizing reservoir is in excess of that in the bmke; pipers, feed valve and means for ohmrg the equalizing reservoir and brake pi rom the min reservoir through the valve when the above specified couneotin means is closed.v

41. In an: air 'braie system embodying an 'equali'z mgi piston ofthat, valve, of means for establtishimgcomnmnicati0n between the upper and lower sides, of the piston, resilient means operaltivrely associated withthe firstna'medi meanscmd' permitting the I pass of -airitherethaoughv when the pressure ve e by- 7 pass to tend to ualize the pressures above and below the plston, substantially as demeans for establishing a normall scribed.

6. In an air brake system, the combination of a brake pipe, an equalizing reservoir, 3 eommumcatlon between the brake pipe and ualizing reservoir, an exhaust valve for M. the brake pipe actuated by a drop of pressure inthe equalizing reservoir, and means actuated by a drop 0 pressure in the brake pipe below the pressure in the equalizing reservoir to reduce the equalizing reservoir pressure.

7. In an air brake system embodying an engineers valve, the combination of a brake pipe, an equalizin reservoir, means normall connecting t e brake pipe with the equa izing reservoir, an exhaust valve for the brake pi actuated by a drop of air pressure in t e equalizin reservoir below that'in the brake plpe, an means independent of the engineers valve for reducing the equalizing reservoir pressure when the brake pipe pressure falls below the equalizing reservoir pressure by a predetermined amount. Signed at New York, N. Y., this 20th day of arch, 1926.

FRANK J. SPRAGUE. 

